From f88ded6c2d771baa7322aaa597f0074b04eefa4d Mon Sep 17 00:00:00 2001
From: Danny Milosavljevic <dannym@scratchpost.org>
Date: Sat, 26 Dec 2020 16:21:58 +0100
Subject: [PATCH] arm-asm: Implement asm_parse_regvar and asm_clobber

---
 Makefile  |  2 +-
 arm-asm.c | 35 ++++++++++++++++++++++++++++++++---
 arm-tok.h | 29 +++++++++++++++++++++++++++++
 tcctok.h  |  3 +++
 4 files changed, 65 insertions(+), 4 deletions(-)
 create mode 100644 arm-tok.h

diff --git a/Makefile b/Makefile
index 19530407..c0cca8c0 100644
--- a/Makefile
+++ b/Makefile
@@ -179,7 +179,7 @@ i386-win32_FILES = $(i386_FILES) tccpe.c
 x86_64_FILES = $(CORE_FILES) x86_64-gen.c x86_64-link.c i386-asm.c x86_64-asm.h
 x86_64-win32_FILES = $(x86_64_FILES) tccpe.c
 x86_64-osx_FILES = $(x86_64_FILES) tccmacho.c
-arm_FILES = $(CORE_FILES) arm-gen.c arm-link.c arm-asm.c
+arm_FILES = $(CORE_FILES) arm-gen.c arm-link.c arm-asm.c arm-tok.h
 arm-wince_FILES = $(arm_FILES) tccpe.c
 arm-eabihf_FILES = $(arm_FILES)
 arm-fpa_FILES     = $(arm_FILES)
diff --git a/arm-asm.c b/arm-asm.c
index f09f0032..6015d550 100644
--- a/arm-asm.c
+++ b/arm-asm.c
@@ -81,13 +81,42 @@ ST_FUNC void asm_compute_constraints(ASMOperand *operands,
 
 ST_FUNC void asm_clobber(uint8_t *clobber_regs, const char *str)
 {
-    asm_error();
+    int reg;
+    TokenSym *ts;
+
+    if (!strcmp(str, "memory") ||
+        !strcmp(str, "cc") ||
+        !strcmp(str, "flags"))
+        return;
+    ts = tok_alloc(str, strlen(str));
+    reg = asm_parse_regvar(ts->tok);
+    if (reg == -1) {
+        tcc_error("invalid clobber register '%s'", str);
+    }
+    clobber_regs[reg] = 1;
 }
 
+/* If T refers to a register then return the register number and type.
+   Otherwise return -1.  */
 ST_FUNC int asm_parse_regvar (int t)
 {
-    asm_error();
-    return -1;
+    if (t >= TOK_ASM_r0 && t <= TOK_ASM_pc) { /* register name */
+        switch (t) {
+            case TOK_ASM_fp:
+                return TOK_ASM_r11 - TOK_ASM_r0;
+            case TOK_ASM_ip:
+                return TOK_ASM_r12 - TOK_ASM_r0;
+            case TOK_ASM_sp:
+                return TOK_ASM_r13 - TOK_ASM_r0;
+            case TOK_ASM_lr:
+                return TOK_ASM_r14 - TOK_ASM_r0;
+            case TOK_ASM_pc:
+                return TOK_ASM_r15 - TOK_ASM_r0;
+            default:
+                return t - TOK_ASM_r0;
+        }
+    } else
+        return -1;
 }
 
 /*************************************************************/
diff --git a/arm-tok.h b/arm-tok.h
new file mode 100644
index 00000000..55232997
--- /dev/null
+++ b/arm-tok.h
@@ -0,0 +1,29 @@
+/* ------------------------------------------------------------------ */
+/* WARNING: relative order of tokens is important.                    */
+
+/* register */
+
+ DEF_ASM(r0)
+ DEF_ASM(r1)
+ DEF_ASM(r2)
+ DEF_ASM(r3)
+ DEF_ASM(r4)
+ DEF_ASM(r5)
+ DEF_ASM(r6)
+ DEF_ASM(r7)
+ DEF_ASM(r8)
+ DEF_ASM(r9)
+ DEF_ASM(r10)
+ DEF_ASM(r11) /* fp */
+ DEF_ASM(r12) /* ip[c] */
+ DEF_ASM(r13) /* sp */
+ DEF_ASM(r14) /* lr */
+ DEF_ASM(r15) /* pc */
+
+/* register macros */
+
+ DEF_ASM(fp) /* alias for r11 */
+ DEF_ASM(ip) /* alias for r12 */
+ DEF_ASM(sp) /* alias for r13 */
+ DEF_ASM(lr) /* alias for r14 */
+ DEF_ASM(pc) /* alias for r15 */
diff --git a/tcctok.h b/tcctok.h
index af8aa9b1..aeac1cd5 100644
--- a/tcctok.h
+++ b/tcctok.h
@@ -370,3 +370,6 @@
 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
 #include "i386-tok.h"
 #endif
+#if defined TCC_TARGET_ARM
+#include "arm-tok.h"
+#endif